Sonic Generations Collection -95% on Steam !

It's a high risk because the offer lasts only 24 hours and a winner has 7 days to accept his win.

If you've got a group you trust, you can probably get a giveaway reliably completed within 24 hours. Conversely, you most definitely don't want to list the game for a public giveaway. Soliciting random entrants off the forums would fall somewhere in the middle. As far as region restrictions, I believe you'd have to check against SteamDB. Can't really rely on Steam for user-friendly functionality..

While this region-disassociated option is the only listing showing as available within the Steam store, this listing's restrictions would appear to be the safer list of regions to attempt to gift to:

Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Great Britain, Iceland, Liechtenstein, Norway, Switzerland, Monaco, Andorra, San Marino, Holy See (Vatican City State), Faroe Islands, Isle of Man, Jersey, Guernsey, Aland Islands, Greenland, Gibraltar, Albania, Bosnia and Herzegovina, Macedonia, Montenegro, Serbia, XK, French Guiana, Guadeloupe, Martinique, Falkland Islands (Malvinas), New Caledonia, Reunion, French Polynesia, Germany, Saint Martin, Mayotte

So, the way to go about it would be to region-lock [and invite-only or group-set] your giveaway, create a thread listing the regions and time restraints, and then invite people to the giveaway. Alternatively, post the game to a pre-existing group like Positive Thoughts, which requires its members to abide by reasonable GA creator requests (if they're listed within the description from the start).

Unfortunately, that's the only group I know of that'd abide by a time restriction [and that more in the sense of users agreeing to deletion requests- it'd be hard to pressure anyone to make a set time window, as RL is unpredictable and, thus, such requests would no longer be "reasonable"], else I'd recommend you additional options.

Same here XD